1. Field of the Invention
The present invention relates to a tool for driving screws and more particularly, to a screwdriver having a removable rod.
2. Description of the Related Art
U.S. Pat. No. 7,287,449 discloses a screwdriver with removable rod, which has set in the grip thereof latching balls (13) at a front side and blocking balls (14) at a rear side. The latching balls are engageable with corner cutouts of the rod to secure the rod in the received or extended position. The blocking balls can enter an annular neck of the rod, assuring the rod in the extended position and prohibiting it from being projected out of the grip. Further, the operating tube (referenced by 7) is inwardly pressable to control the rod from outward projection. This operation manner is inconvenient. The user may actuate the operating tube accidentally, causing the rod to be forced out of the grip. Accidentally projecting the rod out of the grip can scare the user, or cause injury.
Taiwan 201107093 discloses another design of screwdriver with removable rod. This design teaches a rotary control technique instead of press operation, avoiding an accidental actuation of the control member (referenced by 43) to force out the rod. Thus, the rod will spring out only after the user rotated the control member. Further, this design simply uses one set of positioning means (referenced by 41) to engage a front retaining portion (referenced by 32) or rear constraint portion (referenced by 33) of the rod, locking the rod in a received position or extended position. This design eliminates the drawbacks of U.S. Pat. No. 7,287,449, however, the use of one single set of positioning means for locking the rod in the received or extended position, the set of positioning means may be not positively forced into engagement with the constraint portion of the rod as the rod is being forced out of the grip of the screwdriver at a high speed, causing the rod to be ejected out of the screwdriver.